Power seat drive devices for driving a power seat provided on the floor in a motor vehicle may include those disclosed in the following Patent Document 1 and Patent Document 2 as known in the art. The power seat drive device disclosed in Patent Document 1 comprises a ring member attached to a lead screw that rotates in accordance with a power seat motor; a stopper member mounted on the ring member on the lead screw; and a nut member fixed to the seat and mated with the lead screw so that it can move on the lead screw until it impinges on the stopper member.
The power seat drive device can be configured in a reduced number of process steps, with no damage to the lead screw, an excellent appearance after assembly, and a compact exterior of the entire, as known.
The vehicular seat disclosed in Patent Document 2 comprises a common motor for driving the power seat device and a power seat belt device; a seat switch for selecting the use of the power seat device or the power seat belt device; and a changing means for transmitting the power of the motor to either a seat slide mechanism or a retractor changed in accordance with switched state of the seat switch.
The vehicular seat switches between the transmission paths of the drive force to the power seat device and to the power seat belt device to drive these with the common motor, thereby reducing the number of the drive means to reduce the cost. In addition, it facilitates the layout around the seat for installing the motor, and achieves weight reduction, as known.    [Patent Document 1] JP 7-251657A    [Patent Document 2] JP 2007-22153A